Slow access web api

Question

User325876037 posted
Good evening, I can not understand the problem of my web API. everything works correctly but before giving an answer (before entering a function of a controller) it takes about 10/15 seconds. Then the call takes about 1 second. this happens both in debug and compiled. the size does not exceed 5kb so it can not be the size of the data. moreover, the waiting time takes place before the real call. where can I stop debugging to analyze the first command? How can I solve?

Answer 1

User283571144 posted

Hi paciocco7,

According to your description, I couldn't understand your issue clearly.

Do you mean you find the VS start debugging and compiled project takes too long time?

As far as I know, when you click F5 start the project, it will add the process monitor, analiysis tool or something else. So it will take a lot of time.

Best Regards,

Brando

Answer 2

User325876037 posted

To better explain my problem, I uploaded a video. In practice, a desktop program makes a call "CallApi" and the WebApi should immediately enter the "GetRequest" instead there are 5/10 seconds of time and I do not understand why. The "CallApi" function is performed correctly, so it is not possible for the call in the desktop program to process slowly.

Video : https://www.youtube.com/watch?v=YPrwherD-6s&feature=youtu.be

Answer 3

User475983607 posted

The first call always takes longer as the application has to build.  I assume the second request is much faster.  The slowness repeats every time a new debugging session is started.

I run a Web API without debugging when testing or writing client code.  I use unit tests to when writing the Web API.

Answer 4

User325876037 posted

unfortunately it is not like that. also compiled and running IIS does not change. it always takes this time before processing the request. I do not understand the reason.

Answer 5

User475983607 posted

unfortunately it is not like that. also compiled and running IIS does not change. it always takes this time before processing the request. I do not understand the reason.

If there is always a delay then there must be something on your system like a firewall or virus checker.  Try using a network trace tool like wireshark to see what's going on.

Answer 6

User325876037 posted

Code CallAPI function :

System.Net.HttpWebRequest.DefaultWebProxy = Nothing
ServicePointManager.DefaultConnectionLimit = 10
getAuthorization()
Dim origResponse As HttpWebResponse
Dim origRequest As HttpWebRequest
origRequest = CType(HttpWebRequest.Create(link), HttpWebRequest)
origRequest.Headers.Add("Authorization", "Bearer " & TempToken.AccessToken)
origRequest.AllowAutoRedirect = False
origRequest.Method = "GET"
origRequest.Timeout = 1000 * 60 * 10 '5 min
origRequest.Proxy = Nothing
Dim r As New ApiCallStatus
Try
origResponse = CType(origRequest.GetResponse(), HttpWebResponse)   ''' PROBLEMMMMMM
Dim Stream As Stream = origResponse.GetResponseStream()
Dim sr As New StreamReader(Stream, Encoding.GetEncoding("utf-8"))
Dim str As String = sr.ReadToEnd()
Dim jo = Json.Linq.JObject.Parse(str)
Dim joStatus As String = "200"
Dim joDescription As String = "Eleaborazione avvenuta correttamente"
If jo("StatusCode") IsNot Nothing Then
joStatus = jo("StatusCode").ToString
joDescription = jo("ReasonPhrase").ToString
End If
r.Result = str
r.Message = joDescription
r.Link = link
r.StatusCode = joStatus
r.StatusDescription = joDescription

Catch exRequest As System.Net.WebException
r.Result = "WebException"
r.Link = link
Try
Dim HWR As HttpWebResponse
HWR = (CType(exRequest.Response, HttpWebResponse))
r.StatusCode = HWR.StatusCode
r.StatusDescription = HWR.StatusDescription
Catch exConversion As Exception
r.StatusCode = "0"
r.StatusDescription = exConversion.Message
End Try
r.StatusError = True
End Try

Answer 7

User325876037 posted

can someone help me to make this function asynchronous?

Answer 8

User283571144 posted

Hi paciocco7,

According to your description, I suggest you could try to use GetResponseAsync method to make the function become asynchronous.

More details, you could refer to below codes:

 
    Public Async Function SendRequestAsync(ByVal link As String) As Threading.Tasks.Task
        System.Net.HttpWebRequest.DefaultWebProxy = Nothing
        'ServicePointManager.DefaultConnectionLimit = 10
        'getAuthorization()
        Dim origResponse As HttpWebResponse
        Dim origRequest As HttpWebRequest
        origRequest = CType(HttpWebRequest.Create(link), HttpWebRequest)
        'origRequest.Headers.Add("Authorization", "Bearer " & TempToken.AccessToken)
        origRequest.AllowAutoRedirect = False
        origRequest.Method = "GET"
        origRequest.Timeout = 1000 * 60 * 10 '5 min
        origRequest.Proxy = Nothing
        Dim r As New ApiCallStatus
        Try

            origResponse = CType(Await origRequest.GetResponseAsync(), HttpWebResponse)   ''' PROBLEMMMMMM
            Dim Stream As Stream = origResponse.GetResponseStream()
            Dim sr As New StreamReader(Stream, Encoding.GetEncoding("utf-8"))
            Dim str As String = sr.ReadToEnd()
            Dim jo = Json.Linq.JObject.Parse(str)
            Dim joStatus As String = "200"
            Dim joDescription As String = "Eleaborazione avvenuta correttamente"
            If jo("StatusCode") IsNot Nothing Then
                joStatus = jo("StatusCode").ToString
                joDescription = jo("ReasonPhrase").ToString
            End If
            r.Result = str
            r.Message = joDescription
            r.Link = link
            r.StatusCode = joStatus
            r.StatusDescription = joDescription

        Catch exRequest As System.Net.WebException
            r.Result = "WebException"
            r.Link = link
            Try
                Dim HWR As HttpWebResponse
                HWR = (CType(exRequest.Response, HttpWebResponse))
                r.StatusCode = HWR.StatusCode
                r.StatusDescription = HWR.StatusDescription
            Catch exConversion As Exception
                r.StatusCode = "0"
                r.StatusDescription = exConversion.Message
            End Try
            r.StatusError = True
        End Try
    End Function


    Public Class ApiCallStatus
        Public Result As String
        Public Message As String
        Public Link As String
        Public StatusCode As String
        Public StatusDescription As String
        Public StatusError As String

    End Class
 

Best Regards,

Brando